diff --git a/pw_env_setup/docs.rst b/pw_env_setup/docs.rst
index e6d9fb7..06e3295 100644
--- a/pw_env_setup/docs.rst
+++ b/pw_env_setup/docs.rst
@@ -167,8 +167,23 @@
 .. _sample project: https://pigweed.googlesource.com/pigweed/sample_project/+/master
 
 ``cipd_package_files``
-  CIPD package file. JSON file consisting of a list of dictionaries with "path"
-  and "tags" keys, where "tags" is a list of strings.
+  CIPD package file. JSON file consisting of a list of dictionaries with "path",
+  "platforms", and "tags" keys. An example is below.
+
+.. code-block:: json
+
+  {
+    "path": "infra/3pp/tools/go/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
+    "tags": [
+      "version:2@1.16.3"
+    ]
+  },
 
 ``virtualenv.gn_targets``
   Target for installing Python packages. Downstream projects will need to
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/luci.json b/pw_env_setup/py/pw_env_setup/cipd_setup/luci.json
index 240a571..ef62430 100644
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/luci.json
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/luci.json
@@ -1,42 +1,83 @@
 [
     {
         "path": "infra/tools/bb/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
         "path": "infra/tools/luci-auth/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
         "path": "infra/tools/luci/gerrit/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
         "path": "infra/tools/luci/gitiles/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
         "path": "infra/tools/luci/cas/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
         "path": "infra/tools/luci/led/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "linux-arm64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
     },
     {
-        "path": "infra/tools/luci/logdog/logdog/${os}-${arch=amd64}",
+        "path": "infra/tools/luci/logdog/logdog/${platform}",
+        "platforms": [
+            "linux-amd64",
+            "mac-amd64",
+            "windows-amd64"
+        ],
         "tags": [
             "latest"
         ]
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
index 2ca677c..0eb60f0 100644
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
@@ -1,120 +1,207 @@
 [
   {
-    "path": "gn/gn/${os}-${arch=amd64,arm64}",
+    "path": "gn/gn/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "git_revision:39a87c0b36310bdf06b692c098f199a0d97fc810"
     ]
   },
   {
-    "path": "infra/ninja/${os}-${arch=amd64}",
+    "path": "infra/ninja/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:1.9.0"
     ]
   },
   {
-    "path": "infra/cmake/${os}-${arch=amd64}",
+    "path": "infra/cmake/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:3.16.1"
     ]
   },
   {
     "_comment": "TODO(pwbug/93): Package Bazel for Windows.",
-    "path": "fuchsia/third_party/bazel/${os=linux,mac}-${arch=amd64}",
+    "path": "fuchsia/third_party/bazel/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64"
+    ],
     "tags": [
       "version:4.0.0"
     ]
   },
   {
-    "path": "pigweed/third_party/bloaty-embedded/${os=linux,mac}-${arch=amd64}",
+    "path": "pigweed/third_party/bloaty-embedded/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64"
+    ],
     "tags": [
       "git_revision:2d87d204057b419f5290f8d38b61b9c2c5b4fb52-2"
     ]
   },
   {
-    "path": "pigweed/third_party/gcc-arm-none-eabi/${os}-${arch=amd64}",
+    "path": "pigweed/third_party/gcc-arm-none-eabi/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:10-2020-q4-major"
     ]
   },
   {
-    "path": "infra/3pp/tools/protoc/${os}-${arch}",
+    "path": "infra/3pp/tools/protoc/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:3.14.0"
     ]
   },
   {
     "_comment": "TODO(pwbug/70) Put clang in cipd for Windows.",
-    "path": "fuchsia/third_party/clang/${os=linux,mac}-${arch}",
+    "path": "fuchsia/third_party/clang/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64"
+    ],
     "tags": [
       "git_revision:3dc24bc31edbc01dea085b24a6a6b024d7ae531c"
     ]
   },
   {
     "_comment": "When bumping the minor version (e.g., to 3.9.x) also update env_setup/virtualenv/init.py to check for the new version.",
-    "path": "infra/3pp/tools/cpython3/${os}-${arch}",
+    "path": "infra/3pp/tools/cpython3/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:3.8.2.chromium.10"
     ]
   },
   {
     "path": "infra/3pp/tools/go/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:2@1.16.3"
     ]
   },
   {
-    "path": "pigweed/third_party/protoc-gen-go/${os}-${arch=amd64}",
+    "path": "pigweed/third_party/protoc-gen-go/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "version:1.3.2"
     ]
   },
   {
     "_comment": "TODO(pwbug/66) Put openocd in cipd for Windows.",
-    "path": "pigweed/third_party/openocd/${os=linux,mac}-${arch=amd64}",
+    "path": "pigweed/third_party/openocd/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64"
+    ],
     "tags": [
       "git_revision:e41c0f4906e46d1076ce62a0da5518aa1ca280b8"
     ]
   },
   {
-    "path": "pigweed/third_party/mingw64-x86_64-win32-seh/${os=windows}-${arch=amd64}",
+    "path": "pigweed/third_party/mingw64-x86_64-win32-seh/${platform}",
+    "platforms": [
+        "windows-amd64"
+    ],
     "tags": [
       "version:10.2.0-11"
     ]
   },
   {
-    "path": "pigweed/host_tools/${os}-${arch=amd64}",
+    "path": "pigweed/host_tools/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "mac-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "git_revision:3f00a3eb4957306eab148fe3651844e46df5b379"
     ]
   },
   {
-    "path": "infra/rbe/client/${os=linux,windows}-${arch=amd64}",
+    "path": "infra/rbe/client/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "windows-amd64"
+    ],
     "tags": [
       "git_revision:8e834982e020c12b7c3c1f106961cead3d65dec1"
     ]
   },
   {
-    "path": "fuchsia/third_party/qemu/${os=linux,mac}-${arch}",
+    "path": "fuchsia/third_party/qemu/${platform}",
+    "platforms": [
+        "linux-amd64",
+        "linux-arm64",
+        "mac-amd64"
+    ],
     "tags": [
       "git_revision:841f14e74f5af7886cf49cfcd4fed264911ae58e"
     ]
   },
   {
     "path": "fuchsia/third_party/kythe",
+    "platforms": [
+        "linux-amd64"
+    ],
     "subdir": "kythe",
     "tags": [
       "version:1.0.2"
     ]
   },
   {
-    "path": "fuchsia/third_party/kythe-libs/${os=linux}-${arch=amd64}",
+    "path": "fuchsia/third_party/kythe-libs/${platform}",
+    "platforms": [
+        "linux-amd64"
+    ],
     "subdir": "kythe",
     "tags": [
       "version:2020-08-05"
     ]
   },
   {
-    "path": "infra/3pp/tools/renode/${os=linux}-${arch=amd64}",
+    "path": "infra/3pp/tools/renode/${platform}",
+    "platforms": [
+        "linux-amd64"
+    ],
     "tags": [
       "version:2@renode-1.11.0+20210306gite7897c1"
     ]
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/update.py b/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
index c4301ec..922d589 100755
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/update.py
@@ -24,6 +24,7 @@
 import argparse
 import json
 import os
+import platform
 import re
 import shutil
 import subprocess
@@ -148,9 +149,28 @@
     return True
 
 
+def _platform():
+    osname = {
+        'darwin': 'mac',
+        'linux': 'linux',
+        'windows': 'windows',
+    }[platform.system().lower()]
+
+    if platform.machine().startswith(('aarch64', 'armv8')):
+        arch = 'arm64'
+    elif platform.machine() == 'x86_64':
+        arch = 'amd64'
+    elif platform.machine() == 'i686':
+        arch = 'i386'
+    else:
+        arch = platform.machine()
+
+    return '{}-{}'.format(osname, arch).lower()
+
+
 def write_ensure_file(package_file, ensure_file):
     with open(package_file, 'r') as ins:
-        data = json.load(ins)
+        packages = json.load(ins)
 
     # TODO(pwbug/103) Remove 30 days after bug fixed.
     if os.path.isdir(ensure_file):
@@ -161,10 +181,14 @@
                    '$VerifiedPlatform mac-amd64\n'
                    '$ParanoidMode CheckPresence\n')
 
-        for entry in data:
-            outs.write('@Subdir {}\n'.format(entry.get('subdir', '')))
-            outs.write('{} {}\n'.format(entry['path'],
-                                        ' '.join(entry['tags'])))
+        for pkg in packages:
+            # If this is a new-style package manifest platform handling must
+            # be done here instead of by the cipd executable.
+            if 'platforms' in pkg and _platform() not in pkg['platforms']:
+                continue
+
+            outs.write('@Subdir {}\n'.format(pkg.get('subdir', '')))
+            outs.write('{} {}\n'.format(pkg['path'], ' '.join(pkg['tags'])))
 
 
 def update(